The NHS Management Executive recommends that hospitals should aim
to use 90% of planned theatre time and that theatre utilisation should
be used as a key performance indicator. This study aims to investigate
the impact of latestarts and overruns on theatre utilisation rates. Data
were retrieved from a prospectively updated theatre database for all
elective plastic surgical main theatre operating sessions carried out
over a one year period. Theatre list utilisation was calculated as the
percentage of the total allocated session time that was used for
anaesthesia and operating. A total of 2,944 elective main theatre
operations were performed in one year. Total theatre utilisation was
90.9%. Utilisation of lists starting less than one hour after the
scheduled start time was similar to the utilisation of sessions starting
more than one hour late (90.1% versus 91 7% respectively, p=0.527). In
contrast, overrunning lists demonstrated much higher utilisation rates
than those that finished before the end of the session (96.7 % versus
76.6% respectively, p<0.001). The study shows that late-starts and
overruns represent obvious sources of theatre inefficiency yet their
impact on utilisation is misleading: overruns exaggerate theatre usage
and late-starts have little impact upon it. We conclude that the use of
utilisation as a marker of theatre performance requires caution.

Health services worldwide are currently undergoing a period of
economic turbulence (Al-Benna 2010). Healthcare providers, in both
public and private sectors, are facing increasing pressure to improve
cost efficiency and productivity (Al-Benna 2010, 2012). Clinical
activity in the hospital is closely monitored and the target is to
provide high quality of care at the lowest possible costs. It has been
estimated that 29% of all healthcare outlays are related to surgical
expenditure, therefore the efficient use of operating theatres in
hospitals has assumed a great importance in healthcare cost (Munoz et al
2010).

This problem of allocating a given amount of resources in the best
way possible is not new from an economic point of view. Theatre
utilisation has long been used in the UK as an indicator to measure the
efficiency of the use of hospital resources such as the operating rooms
(NHS Management Executive 1989, Audits Commission for Scotland 1999,
Audit Commission 2003, Northern Ireland Audit Office 2003, NHS Institute
for Innovation and Improvement 2009). Researchers often argue that high
utilisation equals cost-effectiveness and goes hand in hand with high
quality of health care (Evans 2009, Al-Benna 2010, Munoz et al 2010). In
these studies utilisation is typically considered as an absolute measure
that can be used to resolve the perceived efficiency problem in
healthcare (Faiz et al 2008, OECD 2010).

In accordance with this trend, UK governmental institutions have
produced key reports on theatre utilisation, and offered programmes to
improve theatre utilisation (NHS Management Executive 1989, Audits
Commission for Scotland 1999, Audit Commission 2003, Northern Ireland
Audit Office 2003, NHS Institute for Innovation and Improvement 2009)The
reports showed that theatres were being used for only about 70-88% of
scheduled time and recommended that hospitals should aim to use 90% of
planned theatre time. The publications from these governmental
institutions have served to enhance the profile of this performance
indicator in the public setting, but there has been little research to
date investigating its validity as a performance indicator. The aim of
this study was to investigate the impact of late-starts and overruns on
theatre utilisation rates.

Methods

Data were collected retrospectively from the operating theatre
database of St. John's Hospital, Howden, Livingston, Scotland which
contained records of each operation performed. To ensure a large enough
sample size, data were collected from all elective plastic surgical main
theatre operating sessions carried out over a one year period. Only
elective plastic surgery was included. Those cases performed on weekends
and public holidays were excluded as there was no scheduled plastic
surgery theatre on these days. Each operation record stored on the
database provides a summary of the procedure performed, the staff
involved and the times at which certain events occurred. For each
operation during the one year period, the following times were recorded:

* Time patient sent for Time in theatre reception

* Time in anaesthetic room

* Time anaesthetic starts

* Time of first incision

* Time out of theatre

The data were collected and entered onto a Microsoft Excel
spreadsheet. Based on these times, the following was calculated for each
procedure:

* Time patient sent for - Time in theatre reception

* Time in theatre reception - Time into anaesthetic room

* Time into anaesthetic room - Time anaesthetic starts

* Time anaesthetic starts - Time of first incision

* Time anaesthetic starts - Time out of theatre

Operating theatre schedules were also collected during this one
year period, enabling the start time and the allocated theatre time for
each elective plastic surgery list to be recorded. Late-starts were
calculated as the time that anaesthesia commenced on the first case
minus the scheduled start time. Overruns occurred where the last case
finished after the scheduled end of the session. Theatre list
utilisation was calculated as the percentage of the total allocated
session time that was used for anaesthesia and operating. All of the
above recorded times were rejected as being normally distributed
(Kolmogorov-Smirnov test), and hence, median values were calculated and
analysed with Mann-Whitney U-tests (MINITAB[TM] Statistical Software,
Release 13.1, Minitab Inc., State College, PA, USA).

Results

In total, 2,944 operations within elective plastic surgery sessions
during the one-year period fitted the criteria for inclusion into this
study. In each case, the operative records were complete, and the
required data was recorded for analysis.

The median Time patient sent for - Time in theatre reception was 11
min (range 1-75 min). The median Time in theatre reception - Time into
anaesthetic room was 11 min (range 1-190 min). The median Time into
anaesthetic room - Time anaesthetic starts was 6 min (range 1-53min).
The median Time anaesthetic starts room - Time of first incision was 10
min (range 1-58min). The median Time anaesthetic starts room - Time out
of theatre was 63 min (range 5-688min).

Only 20.4% of elective lists started less than one hour after the
scheduled start. Overall, 79.6% of lists started over one hour late and
17.9% overran their intended session duration. The theatre utilisation
when lists started less than one hour after the scheduled start time was
similar to the utilisation when lists started more than one hour late
(90.1% versus 91.7% respectively, p=0.527). In contrast, overrunning
lists demonstrated much higher utilisation rates than those that
finished before the end of the session (96.7 % versus 76.6%
respectively, p < 0.001).

Conclusions

In a theoretically efficient operating system, the theatre should
start on time, no operation should be cancelled and the theatre should
finish on time. Increased elective throughput through improved
utilisation of the operating theatre allows scheduling of more elective
surgery.

The aim of this study was to determine the theatre utilisation rate
over a one year period, with data available for all consecutive elective
plastic surgery operations done during this period. More importantly,
the study investigated the impact of late-starts and overruns on
utilisation rates.

In the current survey of 2,988 elective plastic surgery operations
theatre utilisation was 90.9%. The mean theatre utilisation when lists
started less than one hour after the scheduled start time was similar to
the mean utilisation when lists started more than one hour late.
However, overrunning lists demonstrated much higher utilisation rates
than those that finished before the end of the session (see Figure 1).

This study demonstrates that late-starts and overruns represent
obvious sources of theatre inefficiency, yet their impact on theatre
utilisation rates is misleading as overruns exaggerate theatre usage
whereas late-starts have little impact upon it. Therefore, sceptiscism
regarding the validity of a 'target' utilisation rate for
theatres should be maintained.

In the future, quantitative measures of surgical service workload,
such as human resource group tariffs, are likely to prevail over theatre
utilisation rates. Definition of an actual service 'output' in
hospitals has aided political and strategic as well as operational
decision-making. Irrespective however of the validity of a specific tool
that quantifies theatre effectiveness, improving elective theatre
efficiency demands a broad perspective over the entire surgical pathway.

Looking at ways of decreasing theatre time wastage, it appears that
nothing can be done about anaesthetic and operating times, which will
vary depending on the needs of the individual patient. This supposition
could be challenged as it is widely accepted that an increase in
operating times contributes to increased morbidity. However, it is
difficult to define the cut-off for an 'acceptable' time for
anaesthesia and surgery, as there is always a fine balance between speed
and safety.

At present, although '90% theatre efficiency' is regarded
as a goal, the term is incompletely defined and variously interpreted,
making it an almost redundant aspiration. In addition this study
demonstrates that factors beyond occupancy of theatre time are important
in running an efficient theatre service. This has important consequences
for hospital expenditure, hospital income and the clearing of waiting
lists.

Activity and theatre utilisation should be monitored regularly to
assess the time distribution of surgical cases. This monitoring enables
the department to highlight causes of inefficiencies and has been shown
to improve the activity in elective theatres. Given that hospitals incur
costs regardless of whether theatre time is used, the avoidance of
wasted time and maximisation of operating time should help to reduce the
pressure on waiting lists It is easy to measure when a list starts and
finishes but that is a remarkably poor measure of whether the time in
between was used efficiently.

The Productive Operating Theatre is a comprehensive package of
support that has been coproduced and tested by the NHS Institute for
Innovation and Improvement (2009) working with NHS theatre teams. It has
been designed to enable organisations in the NHS to improve the patient
experience and the outcomes of care by pursuing three main goals:

a) increase the safety and reliability of care

b) improve team performance and staff wellbeing

c) add value and improve efficiency.

Many NHS trusts have focused on theatre efficiency metrics, but it
is important to have developed integrated measures that include clinical
quality, safety, patient experience and service reliability - as well as
productivity (Al-Benny 2010).

Late-starts and overruns represent obvious sources of theatre
inefficiency yet their impact on utilisation is misleading as overruns
exaggerate theatre usage and late-starts have little impact upon it.
Studies such as this may help to identify areas in which time may be
more efficiently used and may confirm best practice. Late starts and
unutilized time between cases is an area where improvement is possible.
This is especially true of starting on time. Therefore, the use of
theatre utilisation as a marker of theatre performance requires caution.

Theatre 1 has one case scheduled that starts and finishes on time,
therefore theatre utilisation is 100%.

Theatre 2 has five cases that start and finish on scheduled time,
all five cases overlap as the next patient was in the anaesthetic room
before the current patient left theatre, therefore theatre utilisation
is greater than 100%.

Theatre 3 has four cases that start and finish on scheduled time,
all cases are serial, therefore theatre utilisation is less than 100%.

Theatre 4 has four serial cases that start on time but overrun If
the theatre is utilised for over 8 hours the total may be greater than
100%.

Theatre 5 has one case that starts late and overruns, but if the
total time for 'Time anaesthetic starts room - Time out of
theatre' is over 8 hours, theatre utilisation is greater than 100%.